Improvement in marinerss compasses



H. A. SEVERN.

Mariner's Compass.

Patented May 13, 1879.

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UNITED STATES PATENT OEEIoE.

HENRY A. SEVEHN, OF N6. 9 EARLS' COURT Styli TYRE, COUNTY OF MIDDLESEX, ENGLAND.

IMPROVEMENT IN MARlNERS COMPASSES.

Specification forming part of Letters Patent No. 215,403, dated May 13, 1879; application filed March 11, 187

To all about 2'' may concern:

Be it known that I, HENRY AUGUsTUs SEVERN, No. Ii Earls Court Square, in the county eillriddlesex, England, have invented an Improvement in Mariners Compasses, and in appliances used in connection therewith for indicating deviations from the ships true course; and (lOillQIGlJy declare that the follow ing description, taken in connection with the accompanying drawings, hereinafter referred to, forms a full and exact specification of the same, wherein have set forth the nature and principles of my said improvement, by which my invention may be distinguished from 0th ers of a similar class, together with such parts as I claim and desire to secure by Letters Patout-that is to say:

My invention hasi'or its object to provide means whereby any deviation between optional limits from the prescribed course of a vessel at sea is indicated to the captain or ofiicer in charge by means of an audible or visible signal at any convenient part of the vessel, so that he may at once be apprised thereof, and thus the danger or loss of time attendant on the ships continuing for a length of time on a wrong course unnoticed be obviated.

For this purpose I avail myself of the practically stationary position of the card of the compass in respect of the magnetic meridian, and of the changing position of the box or binnacle surrounding the card as it shifts with the vessel, in order to cause certain electrical contacts to be made when the vessel deviates to a certain extent from its course, and by such contacts 1' cause an electrical circuit to be is included a battery and a signaling appara tus actuated thereby, and the other end of which circuit 1' electrically connected to a spinpatented in England, January 17, 1879.

dle passing centrally through the glass lid of the compass. The spindle is held in the lid so as to be rotatable therein and beneath it. It has a metal arm orin dex projecting radially from it, so that such index can be turned by means of its spindle to any point of the coinpa-ss. A second such metal index is fixed to a metal sleeve fitting the spindle, so as to be rotatable thereon, and also passing through to the outside of the lid, so that both indexes can be set independently to any desired angular position relatively to each other by means of the spindle and the sleeve. The center of the compass-card, in which the metal point bears, is also of conducting metal, insulated from the needles themselves, but in electrical connection with a metal contact piece or arm projecting from the upper face of the card by preference at the north point thereof. The beforementionedindexeshavesuspendedlooselyfrom them small pieces of platinum wire, so that whenever, by the rotation of the bowl in one direction or the other, as it shifts with the vessel, the one piece of wire or the other comes in contact with the arm or the card, the electric circuit will be closed, and the current will actuate the signal.

Thus, in operating with this apparatus, after the captain or oiiicer has determined the course of the ship, he set-s the two indexes so that each one is one or more points away from each side of the contact-arm of the compasscard, the amount depending upon the limits within which a deviation may be allowed. Should now the course of the ship be altered to the extent of such limit, the before-described con tact will be made, and the officcr will be apprised thereof by the actuation of the signal.

The above arrangement may either be applied to the ships compass at the helm, in which case, after the indexes have been set, the external buttons for them may be inclosed by a locked glass cover, or the arrangement may be applied to a special compass in the captains or ofliccrs cabin, in which case the whole apparatus, including the battery and the signaling apparatus, may conveniently be inclosed in a portable box.

By preference an electricalarm bell is em ployed as the signaling apparatus, and in this viation of the ships course in one direction, the

second index may be turned out of the way; or both indexes maybe capable of being raised,

so that their pendent wires cannot make contact with the arm of the card when no signaling is desired.

Figure 1 of the accompanying drawings shows a plan, and Fig. 2 a vertical section,.of a mariners compass with my before-described invention applied thereto.

The compass-cardA has a metal center, A

which rests on the metal point B, and has a metal arm, A projecting from it over the upper surfaceof the card, preferably at the north point. The point B is insulated at B from the bowl, and has connected to it the one end of the circuit-wire G, leading to the battery E and electric bell or other signaling apparatus F, the other end of the circuit-wire being connected at G to the gimbals D of the compass.

From the lid G of the compass, which is in electrical connection with the gimbals D, a metal wireogstri nlil, (represented by a dotted line,) passes across the glass to the center, where it is time-many connected to the metal socket I, fixed in the glass. Through this socket passes a tubular metal piece, K, having at its outer end a button, K, and on its inner end a metal arm, K from which is loosely suspended a piece of thin platinum wire, K Through the tubular piece K passes a metal rod, L, having a button, L, and on its inner end a metal arm, L from which is suspended the platinum wire L The tube K being free to turn in the socket I, and the rod L being free to turn in the tube,

while all three are in electrical contact with each other and with the metal strip H, it will be seen that the arms K and L can be set to any desired angle on either side of the arm A 7 and that should the bowl be turned in the one direction or the other relatively'to' the card A to such an extent as to cause the arm A to con'1e'in contact with the one or the other of the wires K or L the electric circuit formed by the wire 0 will be closed, and consequently the bell or other signal at F will be actuated.

Thus, assuming that the captain or oflicer in charge, after determining the course on which the ship is to be kept, sets each of the arms K L to an angle on either side of the arm A corresponding to the limits within which a deviation from the prescribed course may be allowed, then on these limits being exceeded a contact will be made and a signal given, as above described, whereby the captain or oflicer will be apprised of the fact.

The tube K, together with the rod L, can slide up and down through the socket I, so

that when it is not desired to use the apparatus the arms K L can be raised sufficiently to lift the wires K L out of the reach of the arm A or the one or other of the arms may alone be raised when it is desired to indicate the deviations of the ships course in one direction only, as before mentioned.

In order to provide two bells or other signals-one for indicating the deviations to port,

' and the other for those to starboard, as before mentioned-two separate electrical circuits with'a battery and signal would be required, the one circuit being connected to the tube K with its arm K and the other being connected to the rod L with its arm L whilethe other terminal of both circuits would be connected to the point B. In this case the tube K and rod L would, of course, have to be insulated from each other.

Instead of providing only one bell in the electrical circuit or circuits, there might be provided two or more at different parts of the ship, such as in the captains cabin and in the cabin of the second officer, so that each might be apprised of the deviations from the prescribed course.

It will be evident that numerous other modifications might be adopted for carrying my invention into practice. Thus each of the arms K and L might be made to constitute the two insulated terminals of either a single electrical circuit common to both or of two separate circuits, and the compass-card be simply provided with a contact-piece which, in coming in contact with the two terminals of the one or other arm, would close the circuit and give the desired signal. Also, in place of having the two arms connected to the center of the compass-lid, they might be carried by slides capable of being shifted round the inner circumference of the compass-bowl; but I prefer the arrangement above described as being the most simple.

I am aware that a compass has been invented in which the card carries a contact piece, and contact-points are arranged in a circle in the path of said contact-piece, thus requiring a multiplicity of terminals, and I do not claim such invention. I obviate this multiplicity of terminals by using only two adjustable central points or circuit-terminals, thus greatly lessening the cost and increasing the convenience of the compass.

Having thus described the nature of my in vention, and in what manner the same is to be performed, I claim- 1. In mariners compasses, an arm or contactpiece carried by the compass-card, in combi nation with one or more adjustable insulated arms or contact-pieces carried by the compass lid or bowl, and connected to an electrical circuit in which is included one or more electrical bells or other electrical signals, whereby the angle may be regulated'within which de viation from the ships course may be allowed, and deviation in excess of said angle indicated by the contact of the contact-pieces on the card with either of the adjustable arms or contactpieces, and the consequent closing of the electrical circuit and operation of the signal included therein.

2. A compass card with arm or contactpiece in electrical connection with the one pole of a battery, in combination with one or more adjustable insulated arms carried by the compass bowl or lid, and in electrical connection with the other pole or" the said battery, and with an electrical signaling instrument, substantially as and for the purposes herein set forth.

3. The combination of the arm A carried by the compass-card A, and connected to the one pole of a battery E, with the two adjustable arins K L connected to the other pole of the battery E and the signa1ing-instru ment, substantially as herein set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing Witnesses, this 13th day of February, 1879.

HENRY A. SEVERN.

Witnesses:

CHARLES BENTON ABEL, HARRY EDWARD HOPKINS. 

